Sound-producing device



-load on the latter.

practice in all horns of this type, the wide I nuns-p; STAT-ES PATENT OFFICE.

101m 11. wnrirmociit, or woncrsrnn, MASSACHUSETTS, ASSIGNOR T0- KLAXON com- PANY, or nnwnnx, NEW JERSEY, a conrom'rron or DELAWARE.

son m-rnonucme DEVICE.

To all whom it may concern:

Be it known that 1, JOHN H. Wrrnnnoon,

, a citizen of the United States, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented a new Device, of

positively during a part only of the swing of the diaphragm and on the return movement of the diaphragm necessarily acts as a According to modern effective swings of the diaphragm occur a "when certain definite speeds are obtained.

In such cases, the weight of the thrust mem- 5 her acts to retard, graduate and smooth out the swim 'movements of the diaphragm, and

I have scovered that at speeds where the amplitude of .swing of the diaphragm is I vibrating "with maximum 'mechanical efiigreatest and the most powerful sound wave is being generated, the note may be too smooth to produce maximum soundeffect on the human ear.

My present lnvention depends upon the discovery that when the diaphragm s thus c'ien'cy, with very disproportionate sound effect on the ear, the volume of soundmay be enormously increased byadjustinga perfectly rigid abutment having a rigid face to a pointwhere it barely contacts with the bellying portion of the diaphragm at .the extreme limit of its swing, preferably the outward swin the plunger. 11 such cases, if a hard metallic abutment rigidly supported is screwed toward the diaphragm, the instant .the

swinging diaphragm. touches it, the-volume of sound is tremendously increased, but

without any apparent interference with the mechanical efiiciency' and wide swinging of the diaphragm. a

My invention may be more fully understood from the following detailed description thereof in connection with the accompanying drawing in which- "Figure 1 is an end elevation of a horn which is the one forced by' H Specification of Letters Patent. I Patented Aug, 30, 1'921 Application filed December 81, 1917. Serial No. 209,770. I

sluawing one embodiment of this invention, an i H I l Fig. 2 is a longitudinal central sectional view of a double horn showing several modificatlons.

The inventlon is shown in Fig 1 as ap- =plied to a horn of simple character having a vibrating diaphragm 11 held at its edges by he ng'clamped between two plates 12 and 13 constituting part of the casing of the horn. The diaphragm is shown as vibrated by a thrust member 15 operated by an elecmittent. The abovemamed features are simply selected from the well-lmown types of "horns, and it is to be understood thatthis invention is notlimited to that particular construction. 7

The feature of. the invention shown in -th1s figure is the attachment to the casing .tro'magnetlfi either alternating or intermanufacture a mere projection can be placed or formed on the casing plate and originally made in the proper location to cause the maximum sound to be produced.

While merely unscrewing the-abutment 17 out of range of the diaphragm will usually reduce the sound as much as ordinarily desirable, the device is shown as provided with 1 a deadening screw 18 located on a fixed part of the casing and adapted to engage-the diaphragm at a point-near its edge or elsewhere. This screw works entirely differently from the-screw '17 because ordinarily it is not in use, but when it is to be put in use for deadenlng' the sound it is simply screwed up against the diaphra m and firmly so as to remain in contact t erewith andcut down the amplitude of swings of the diaphragm by preventing or partially preventing the vibration of the zoneof the diaphragm beyond the screw. It is for this reason, that it is located at a distance from the edge but at a greater distance from the center because when used it is still desired to have a part of the diaphragm vibrate so as to produce a deadened, sound.

The screw 17 is located near a point of at, or adjusted to, such a distance from the normal position of the diaphragm that when the diaphragm vibrates it will just touch the end of the screw on each vibration. I have found in practice that under certain conditions this adds immensely to the loudness of sound produced and that the sound prothe abutment for'the time being duced by vibrating the diaphragm against such a fixed element is so great as to drown out the sound produced by the mere flexing backand forth of the diaphragm itself, although that usually is at least as great as ordinary horns produce. It will be understood further that when the deadening screw 18 is screwed down it so reduces the amplitude of vibration that the diaphragm will not thereafter engage the screw 17, so that this deadening'screw reduces the sound in two ways; first, by eliminating the use of. and leaving only the ordinary vibration of the dialphragm to produce the sound, and second,

y decreasing the area and amplitude of vibration of the diaphragm.

In the form shown in F ig. 2 most of the parts described in connection with Fig. 1 are present, namely the parts 11, 12, 13, 15, 17 and 18. But two vibrating members or diaphragms 11 are shown and the. plunger or floating vibrator is shown having two ends 15. They are connected together by an eccentric strap 21 so as to move together. The eccentric strap is operated by a cam 22 on a shaft 23 operated by hand or motor (which may be of the direct current type) or b such an, operating device as is used on I laxon horn, for example, The plunger ends l5 can be guided by guides 24 and always engage the-two diaphragms so as to move back and forth with them. The eccentric or cam positively forces the plunger in one direction with the diaphragms and one of the diaphragms preferably is employed as the sole means for forcing it baclq in the opposite direction.

.In this form I have shown the plates 12 and 13 as supporting thediaphragm in a new. way. They have substantially circular contacting surfaces 12 and 13 between which the extreme edge of the diaphragm is held by screws 25 passing through enlarged holes in the dia )hragm and having bushings 26 therein. ne of them as 13 is provided with a wider annular flat surface for receiving the inner edge of the vibrating diaphragm while the other surface on the plate or flange 12 is narrow. This flange is dished out so that the diaphragm never touches it, but as it'vibrates it separates from the inner portion of the surface of 13 and apparently impinges upon its corner with enough force to add somewhat to the volume of sound. I find by experiment that 31 to collect the sound and direct it wherever desired.

In operation the rapid rotation of the shaft 23 causes the two diaphragms to vibrate without any tapping action from the'plunger ends 15*. This produces sufficient sound 1n many types and sizesof horns, but it can always be materially increased by bringing the abutment into action as described above.

Although I haveillustrated and described only two forms of the invention, I am aware of the fact that other modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore I do not wish to be limited to all the details of construction or to the particular types of horn shown, but what I do claim is:

1. In a horn, thecombination of two parallel diaphragms, a thrust member arranged perpendicularly to the two diaphragms and located between them, and always in contact with both, whereby when moved in one direction the plunger will distort one of the diaphragms and both diaphragms will move with it in both directions, and two abutments having rigid surfaces adapted to engage one diaphragm, one of said abutments tending to prevent vibration of one part and the other to limit the amplitude of swing of another part of said diaphragm.

2. A sound producer comprising a pair of parallel diaphragms, a thrust member between them in contact with both, means for moving said thrust member'in one direction toward one diaphragm, the other diaphragm being arranged to move simultaneously in the same direction, and circular members having rigid contact surfaces in position to engage the diaphragms throughout a porwith said diaphragm to deflect the latter, means for maintaining said member incontact with said diaphragm during the return movement of said member by-said' diaphragm, and acircular member having a rigid contact .surface in position-to engage the diaphragm through a'portion only oi? each vibratoly-swing'.

5. A sound producer including a diaphragm; a thrust member, means for moving said thrust member in one direction with said diaphragm to deflect the latter, means for maintaining said member in icontact with said Idiaphragm during the return movement of said member by said diaphragm, and a pair of stops one adapteda portion of the diaphragm and the other en'- gaging with the diaphragm during a per;

tion onlyof the swing of the latter to huntthe amplitude of vibration of the diaphragm.

and limit the movement of said member by said dia- 1 phragm, and an adjustable abutment in the path of movement of the diaphragm and adapted to engage with the diaphragm during a portion only ofthe swing of the latter amplitude of swing ofvthe diaphragm.

7. A device of the character set forth in claim 5 in vwhich the stops are adjacent to each other but at difierentdistances from the center of the diaphragm, the first mentioned stop being at the eater distance.

In testlmony whereo aflixed my signature.

JOHN H. WHEELOGK.

I have hereunto 

